The aim of this application is to improve the Animal Facility of the Monell Chemical Senses Center and facilitate its accreditation by the Association for Assessment and Accreditation of Laboratory Animal Care (AAALAC). A not-for-profit research institute [501(c)(3)], Monell was founded in 1968 with a unique mission to investigate the basic biology of taste and smell. This institute, originally part of the University of Pennsylvania, is in the heart of the University City Science Center, the largest and oldest urban research center in the United States. Monell's research is supported predominantly by the National Institutes of Health and other governmental agencies, such as the U.S. Department of Agriculture. The annual research conducted at Monell totals $16M. Animals -- mostly mice, rats, and ferrets -- are now used by 12 research programs at Monell and account for nearly $6M research dollars spent annually. Most research now is conducted with mice, but in the past, animal studies have used nonhuman primates, meadow voles, musk shrews, mini-swine, and wild-caught animals housed in the facility. Research projects on taste and smell conducted with animals housed at Monell have resulted in discoveries that have influenced the direction and scope of research programs on taste and smell, nationally and internationally. For instance, the sweet taste receptor was identified in a mouse study at Monell, as was the role of the major histocompatibility complex in parents' ability to identify offspring by smell. Monell is also well known for its work on comparative biology. Monell's current facility of animal care was established in 1971. In 1989 it was gutted and rebuilt, in part with NIH funds. The animal care and use program at Monell is well developed: It has operated successfully for the past 43 years and is licensed by the USDA, with no non-compliant findings. Our goal is to update our ~10,800 square foot Animal Facility and obtain accreditation by AAALAC. To accomplish this goal, we need to replace the air-handling unit that supplies the Animal Facility. This unit functions poorly and is in imminent danger of failing due to its age. Its lack of redundancy makes maintenance difficult, because emergency procedures must often be used to support the animal environment while work is performed on it. The prospect of catastrophic failure grows more likely with each passing month. Although temperature and humidity can usually be maintained within the range required for animal safety, these parameters often deviate too much for optimal research conditions, with unacceptable swings in humidity becoming increasingly common. Moreover, the amount of heat recovery has decreased over time and this deficit has accelerated recently due to deterioration of the system's coils. This problem is very difficult to fix, because the tight location of key parts of the unit makes cleaning and servicing the heat exchange coils almost impossible. There is also an immediate concern that leakage in the discharge side of the exhaust ductwork may lead to air-borne contaminants (particulate material) that could affect the health of our animals and interfere with sensory testing in our research programs. Our plan is to replace the aging primary air-handling system with a new system that features redundancy, ease of maintenance access, significantly improved energy recovery, and corrections to the exhaust system to reduce air-borne particulates. This new system is projected to be at least 20% more energy efficient over the existing unit's peak efficiency (which is no longer realized) and will provide significantly better control over temperature and humidity. Monell has a clear line of authority for managing its Animal Facility. Monell's Director supervises the Director of Facilities Management, who manages the Animal Facility and the program of animal care under the guidance of the Institutional Animal Care and Use Committee (IACUC). She has nearly three decades of experience in this role, has managed several major renovations at Monell over the years, and will be the Project Manager. An expert Building Engineer, who is responsible for electrical, plumbing, and mechanical aspects of the buildings, reports to the Director of Facilitie Management. The Principal Investigator of this application is a scientist with 30 years of experience at Monell, with funded projects that rely heavily on mouse breeding and over 100 published papers on animal models of human disease, who also has served on Monell's IACUC. An experienced American College of Laboratory Animal Medicine board-certified laboratory animal Attending Veterinarian has been guiding Monell's program of animal care and use since 1982, including the original design and construction of the Animal Facility, IACUC responsibilities and functions, animal care operations, veterinary care, training, and compliance. The expert Mechanical Engineer that Monell contracted for this application has project management expertise, has participated in many major renovations of this building, and provided detailed line drawings for this application. He complements the expert and experienced team that Monell has assembled for this essential renovation project. Air-handling renovations described in this proposal will result in necessary and important improvements to Monell's facilities of animal care, thereby ensuring the health and safety of its animals and the quality of chemosensory research on which Monell relies. By replacing the most obsolete part of the Animal Facility, we will ensure that environmental conditions for the animals will be within the AAALAC accreditation guidelines.